A significant number of people confined to wheelchairs have body deformities that require a customized back support. These wheelchair occupants require a back support that conforms to the shape of their bodies so that they will have enough contact with the back support to be able to sit upright, without falling over. A custom shaped back support also provides comfort and avoids skin pressure that may result in ducubitus ulcers or other skin problems.
Numerous other wheelchair occupants, while not necessarily needing a wheelchair particularly adapted for handling bodily deformities, require and desire wheelchairs having proper trunk control for good posture and for comfort.
In order to properly fit wheelchair occupants, the backs of the wheelchair are preferably contoured to be able to fit closely to the occupant's body shape to provide support over the occupant's whole back without putting too much pressure on any one point. One approach to achieving this goal is to provide a customized foam cushion, formed in place to fit the wheelchair occupant's back. Another approach is to carve a foam blank to the shape of the occupant's back. Each of these approaches is somewhat deficient because there is no way to change the shape of the foam cushion to accommodate the changing needs of the wheelchair occupant, or to correct errors in the initial shape of the cushion.
Another approach to the problem of properly and easily fitting the foam cushion to meet the needs of the wheelchair occupant is to provide an adjustable hard matrix of metal parts, aligned and adjusted to generally conform to the shape of the occupant's back. The hard metal matrix is then covered by foam and a fabric cover. A disadvantage of this system is that several hours of tedious adjustment are required to properly fit the matrix to the shape of the occupant's back.
Yet another approach to fitting the wheelchair back to the occupant is disclosed in U.S. Pat. No. 5,407,248, issued to Eric C. Jay et al., which is hereby incorporated by reference in its entirety. A rigid back shell extends between the vertical posts of the wheelchair. A padding system consisting of a contoured foam pad is attached to the rigid shell, and fluid-filled pads can be used for cushioning sensitive areas of the occupant's back, such as the spinal area. Further, U.S. Pat. No. 5,407,248 discloses the use of foam blocks removably attached to the seat back by means of hook and loop fasteners, whereby the foam blocks can be removed as needed to form recessed areas generally conforming to the contour of the occupant's back. Further, foam transition blocks can be used to smooth out the contour defined by the foam blocks and the recessed areas. Also, built-up pads can be applied, using hook and loop fasteners, to the front of the foam blocks, or to the seat back in the recessed areas, to further customize the fit of the wheelchair. The support system of U.S. Pat. No. 5,407,248 provides numerous advantages to the wheelchair occupant, particularly in the area of comfort for the mid and upper back regions of the occupant's back. It would be advantageous if there could be developed a support system providing even greater support for wheelchair occupants.